Pool Base Questions

[diyindux]

I did a search but didn't find much in the way of current threads on this topic. I'm in the process of a DIY inground build and I'm getting quite a bit of differing info regarding the base. I've been told only vermiculite works, or only concrete on the flat and slopes and vermiculite on the sides of the hopper, or only use perlite and cement, or sand and cement or just sand. I'm trying to sort it all out. From what I can tell vermiculite is kind to the liner but not the wallet, sand and cement is easier on the wallet but like sandpaper on the liner, concrete is not that cheap and will not be fun to land on, perlite being a volcanic glass isn't the best choice for the liner but is cheaper than vermiculite, and sand is easier on the wallet and the liner but is likely to dent. My soil is all nice clean sand and there are no groundwater issues to contend with. If I just go with a sand bottom, I'll save a bunch of money but I will definitely need to plan on some work when the liner gets replaced. But many builders have cautioned me against going this route. I'm getting a 27 mil liner so I don't see how this will differ from every inground pool built 10 to 15 years ago.

I don't want to cut corners for the sake of a few bucks but with the materials running around $1,100 for the vermiculite and cement I don't want to spend all of the money and time if I'm not going to see much benefit. I can buy the perlite and cement for around $750, and I can use material I have on site for a sand bottom.

 

[msgtdan]

How about the pink foam that is used under above ground pools, I know it's been used on some with hoppers. Seems like I've seen someone on a DIY use it as well.

 

[bk406]

I would do "poolcrete". Basically a mix of cement, bit of sand, and a bit of vermiculite. No aggregate. It's almost like thick thinset mortor. It trowels smooth like concrete, but doesn't make indentations like straight vermiculite. A local concrete company probably makes the mix. It's a bit of a pain to do a liner pool bottom. A lot of DIY'ers actually contract this part out.

Don't use a sand bottom with an IG pool.

 

[diyindux]

By adding sand then I'm back to a more abrasive pool base.

 

[JamesW]

I think that vermiculite would be the best choice. However, it is difficult to do correctly, and it would probably be best to subcontract that part of the build to an experienced crew.

 

[diyindux]

At this point in the season, everyone seems to be totally booked. I'm in the business of grouting soil and rock so I'm familiar with cement and mixing, but I'm sure my troweling will leave something to be desired. I'll just mix it a batch at a time and make sure it goes on smooth. For the shallow end, I'l just mix it wet and add some platicizer to let it flow out flat and take my time on the slopes. The good thing about vermiculite is it can be scraped and patched the next day. I've been told that the best people to help with pool bases are guys that do plaster work so I'm trying to line someone up from the blue board and plaster trade.

If it turns out well I'll post pictures.